254 



Abstracts of the Makerstoun Observations, 1843. 



Variations of the Total Magnetic Force with reference to the Moon's Declination. 



Means of Groups. 



27 days to 1 day, Moon farthest North, 0-000101 



2 5 ... 0000084 



6 8 ... 0-000058 



9 12 ... 0-000041 



13 days to 15 days, Moon farthest South, 0-000072 



16 19 ... 0-000022 



20 22 ... 0-000017 



23 26 ... 0000031 



There seem, therefore, to he maxima of the total magnetic force luhen the moon has its greatest north and 

 south declinations, and minima about the time when the moon is on the equator. The principal maximum occurs 

 when the moon has its greatest north declination, and the principal minimum when it is on the equator mo\'ing 

 northwards ; the secondary maximum and minimum are not shewn so distinctly. 



Variations of the Total Magnetic Force with reference to the Moon's Distance from 



THE Earth. 



Means of Groups. 



6 days after Apogee to 6 days hefore Perigee, 0-000103 

 5 days to 2 days hefore Perigee, 0-000081 



1 day before to 1 day after Perigee, 0-000064 



2 days to 5 days after Perigee, 0-000082 



6 days after Perigee to 6 days after Apogee, 0-000041 

 5 days to 2 days hefore Apogee, 0-000037 



1 day before to 1 day after Apogee, 0-000024 



2 days to 5 days after Apogee, 0-000069 



Extreme Positions. 



TABLE XXVIII. — Differences of the Extreme Readings of the Three Magnetometers from the 

 Monthly Means for the Hours at which they occurred, for each Month in 1843, as deduced from 

 the Nine Daily Observations, together with the Ranges of the Three Magnetic Elements in each 

 Month. 



Month. 



Westerly Declination. 



Bifilar Magnetometer. 



Balance Magnetometer. 





Ranges. 



^c 



Greater than 

 Mean. 



Less than 

 Mean. 



Reading greater 

 than Mean. 



Reading less 

 than Mean. 



Reading greater 

 than Mean. 



Reading less 

 than Mean. 



Decli- 

 nation. 



Horizontal 

 component 



* 



Vertial 

 component. 



1843. 



d. 



h. 



' 



d. 



h. 



' 



d. 



h. 



Sc. Div. 



d. 



h. 



Sc. Div. 



d. 



h. 



Mic. Div. 



d. h' 



Mic. Div. 





1 



Jan. 



16 



2 



+ 4-15 



23 



8 



- 4.64 



16 



6 



+ 9-4 



28 



8 



-12-9 



28 



6 



+ 85-0 



27 18 



- 44-5 



12-70 



000239 



0-00133 ' 



Feb. 



24 



4 



+ 15-95 



6 



10 



-36-75 



12 



20 



+ 100 



14 



10 



-14-5 



24 



8 



+ 123-9 



13 20 



- 47-8 



59-29 



-00267 



-00171 1 



Mar. 



7 



4 



+ 10-94 



29 



10 



-15-41 



18 



6 



+ 19-4 



7 



8 



-24-8 



7 



8 



+ 292-7 



31 



- 52-2 



33-02 



•00474 



-00335 



Apr. 



6 



2 



+ 10-79 



6 



10 



-12-85 



5 



6 



+ 43-9 



5 



10 



-68-8 



5 



6 



+ 344-0 



5 20 



-105-4 



33-38 



•01265 



-00152 



May 



26 



2 



+ 4-22 



6 



10 



-18-44 



10 



6 



+ 18-4 



6 



10 



-79-1 



15 



10 



+ 79-8 



6 10 



-257-2 



29-84 



•01069 



•00303 



June 



30 



2 



+ 7-96 



29 



20 



- 6-50 



30 



6 



+ 13-3 



11 



22 



-10-6 



13 



6 



+ 53-7 



4 18 



- 38-6 



25-60 



-00474 



•00097 



July 



25 



2 



+ 5-55 



24 



10 



-26-31 



25 



4 



+ 96-2 



24 



22 



-42-0 



25 



4 



+ 246-1 



18 



- 56-7 



40-48 



•01627 



-00291 



Aug. 



22 



2 



+ 4-23 



4 



6 



- 8-79 



4 



6 



+ 22-6 



8 



18 



-36-8 



4 



6 



+ 116-1 



8 18 



-1530 



19-86 



•00744 



.00268 



Sept. 



1 



20 



+ 13-00 



18 



10 



- 9-11 



23 



6 



+ 17-4 



18 



22 



-16-4 



5 



6 



+ 51-5 



27 18 



- 46-2 



24-90 



•00508 



•00115 



Oct. 



5 







+ 6-16 



26 



10 



-17-63 



16 



10 



+ 38-1 



4 



22 



- 9-0 



26 



6 



+ 90-8 



4 18 



- 63-8 



31-39 



-00617 



•001651 



Nov. 



6 







+ 5-89 



3 



8 



- 4-22 



24 



2 



+ 10-8 



3 







-10-3 



3 



2 



+ 32-6 



2 18 



- 20-3 



14-20 



•00335 



•00068 



Dec. 



12 



2 



+ 5-45 



11 



8 



-11-22 



8 



20 



+ 15-1 



8 



10 



-18-6 



8 



8 



+ 94-5 



10 18 



- 46-2 



21-82 



-00412 



•00153 













































